Clavis Sigillorum and Index of Manuscripts.--The author's intention
to publish his MSS. (1).--The preparation of the MSS. for
publication (2).--Admonition to readers (3).--The disorder in the
MSS. (4).--Suggestions for the arrangement of MSS. treating of
particular subjects (5--8).--General introductions to the book on
painting (9--13).--The plan of the book on painting (14--17).--The
use of the book on painting (18).--Necessity of theoretical
knowledge (19, 20).--The function of the eye (21--23).--Variability
of the eye (24).--Focus of sight (25).--Differences of perception by
one eye and by both eyes (26--29).--The comparative size of the
image depends on the amount of light (30--39).

II.

LINEAR PERSPECTIVE

General remarks on perspective (40--41).--The elements of
perspective:--of the point (42--46).--Of the line (47--48).--The
nature of the outline (49).--Definition of perspective (50).--The
perception of the object depends on the direction of